Bricklayer{40 s hammer head having wear-resistant chipping end surfaces

ABSTRACT

A forged steel bricklayer&#39;&#39;s hammer head including a blade portion having a chipping end defined by top and bottom bevel faces intersecting along a straight transverse cutting edge and by opposite lateral edges of the blade portion is provided with a layer of tungsten carbide electrodeposited on said chipping end at each of the bevel faces adjacent the cutting edge therealong and at each of the lateral edges adjacent the cutting edge, the layers forming outer surfaces on the bevel faces and the lateral edges and penetrating the blade portion, thereby providing wearresistant surfaces on said chipping end.

H] Elite tates Porter 14 1 Jan. 23, 1973 BRICKLAYERS HAMMER HEAD HAVING WEAR-RESISTANT CHIPPING END SURFACES Inventor: Laurence W. Porter, Hebron, lll.

Assignee: Vaughan & Bushnell Mfg. Co.,

Hebron, 111.

Filed: Oct. 12, 1971 Appl. No.: 188,032

Related U.S. Application Data Continuation of Ser. No. 876,299, Nov. 13, 1969.

U.S. c1. ..125/40 Int. Cl. ..B28d l/26 Field of Search ..145/29; 125/40; 76/D1G. 11;

References Cited UNITED STATES PATENTS 2/1926 Kimber .;..l25/40 1,803,875 5/1931 Stoody ..76/D1G.ll 3,459,917 8/1969 2,260,593 10/1941 3,158,214 11/1964 1,614,055 l/l927 Abraitis ..l25/40 Primary Examiner-Harold D. Whitehead Attorney-Norman H. Gerlach [57] ABSTRACT A forged steel bricklayers hammer head including a blade portion having a chipping end defined by top and bottom bevel faces intersecting along a straight transverse cutting edge and by opposite lateral edges of the blade portion is provided with a layer of tungsten carbide electrodeposited on said chipping end at each of the bevel faces adjacent the cutting edge therealong and at each of the lateral edges adjacent the cutting edge, the layers forming outer surfaces on the bevel faces and the lateral edges and penetrating the blade portion, thereby providing wear-resistant surfaces on said chipping end.

1 Claim, 6 Drawing Figures PATENTEUJAH23 I975 3,712,284

INVENTOR LAURENCE Wv PORTER \v ATTORNEY BRICKLAYER'S HAMMER HEAD HAVING WEAR- RESISTANT CHIPPING END SURFACES This is a continuation of application Ser. No. 876,299, filed Nov. 13, 1969.

This invention relates to portable impact tools and has particular reference to a bricklayers hammer construction.

A bricklayers hammer is a specialized hand tool having a forged steel hammer head which includes a square impact head proper and a chipping blade at opposite ends of the head. The impact head proper is provided with a substantially flat outer face and square corners and edges. The chipping blade has a chisel type outer chipping end terminating in a straight transverse cutting edge. A brick mason breaks a brick by chipping a straight line or groove across one side of the brick with the chipping blade, and then striking the opposite side of the brick with the impact head proper.

It is necessary for breaking bricks evenly or cleanly that the cutting edge of the chipping blade be sharp, to produce a clean cut, and straight without rounding, for chipping a straight line or groove of substantially constant depth across the brick. The chipping takes place under highly abrasive conditions, so that the blade rapidly becomes dull and must be sharpened. Up to several inches of the blade may be removed during the life of a bricklayers hammer, owing to alternate wear and sharpening. As the blade becomes dull and the corners of the chipping edge round off between sharpenings, it becomes more difficult to chip the proper line for a clean break, and the bricks are fractured unevenly.

An object of the present invention is to provide a forged steel bricklayers hammer head, and a hammer embodying the same, having wear-resistant chipping end surfaces which serve to greatly reduce wear of the cutting edge, so that the edge remains sharp and straight, and continues to produce a clean break over long continued use in breaking bricks, without need for sharpening.

Another object is to extend the useful life of a bricklayers hammer by extending the service life of the relatively fast-wearing blade portion of the hammer head thereof.

A specific object is to provide in a forged steel bricklayers hammer head including a blade portion having a chipping end defined by top and bottom bevel faces intersecting along a substantially straight transverse cutting edge and by opposite lateral edges of the blade portion, a layer of tungsten carbide electrodeposited on the chipping end at each of the bevel faces adjacent the cutting edge therealong and at each of the lateral edges adjacent the cutting edge, the layers forming outer surfaces on the bevel faces and the lateral edges and penetrating the blade portion, thereby providing wear-resistant surfaces on the chipping end.

An additional object is to provide a bricklayers hammer head accomplishing the foregoing objects which is readily and economically constructed, requiring but a very simple operation on an otherwise finished tool.

These and other objects, advantages and functions of the invention will be apparent on reference to the specification and to the accompanying drawings, in which like parts are identified by like reference symbols in each of the views, and in which:

FIG. 1 is a perspective view of a bricklayers hammer provided with a head having a wear-resistant chipping end in accordance with the invention;

FIG. 2 is an enlarged perspective view of the chipping end;

FIGS. 3 and 4 are, respectively, englarged top and bottom plan views of the chipping end;

FIG. 5 is a further enlarged side elevational view of the chipping end; and

FIG. 6 is a similarly enlarged longitudinal sectional view of the chipping end.

Referring to the drawings, particularly FIG. 1, a bricklayers hammer 10 constructed in accordance with the invention includes a wooden handle 12 and a forged steel hammer head 14. The head 14 includes a medial body portion 16, an impact head proper l8, and a chipping blade portion or blade 20. The medial body portion 16 is provided with a socket or opening 22 extending therethrough, in which the handle 12 is received. The handle 12 includes a proximal grip section 24 and a distal connecting section 26. The connecting section 26 is inserted in the head socket 22 and second therein by wedge means, not shown.

The impact head proper 18 is integrally joined to the medial body portion by a constricted neck portion 28, with the head proper projecting outwardly from one end of the body portion. The chipping blade portion 20 is integral with the body portion 16 and projects outwardly from the opposite end thereof. A top side 30 on the head 14 forms the top side of the head proper 18 and of the chipping blade portion 20, being convexly curved in the regions of the body portion and the blade portion.

The impact head proper 18 is cubically shaped and includes a substantially flat and square striking face 32 and four sides substantially perpendicular thereto and to adjacent sides. The corresponding end 30a of the top side 30 of the head 14 constitutes the top side of the head proper 18, and a pair of parallel lateral sides 34 adjoin the top side. A bottom side 36 adjoins the lateral sides 34 and is parallel to the top side 30a. The resulting comers 38 and edges 40 on the head proper 18 at the striking face 32 are square.

The chipping blade portion 20 includes a pair of opposite narrow, divergent lateral edges 42 extending from the medial body portion 16 to a chipping end 44 of the blade portion. The corresponding end 30b of top side 30 of the head 14 constitutes the top side of the blade portion 20, and a bottom side 46 of the blade portion is curved concavely and converges with the top side 30b in the direction of the chipping end 44.

As more clearly shown in FIGS. 2,5 and 6, the chipping end 44 is defined by a relatively narrow top bevel face 48, a relatively wide bottom bevel face 50, and by the opposite lateral edges 42 of the blade portion 20. The bevel faces'48 and 50 intersect along a substantially straight transverse cutting edge 52. The chipping end 44-as thus formed is a chisel type cutting end, which is preferred for supporting and preserving the cutting edge 52, without becoming distorted or broken.

The hammer head 14 is constructed of forged steel, suitably heated, annealed, ground and finished, to provide a Rockwell C hardness of 50-57 on the impact head proper 18 and the chipping bladeportion 20. The hammer head is constructed of high carbon steel (e.g.,

about 0.8 percent carbon as in A181 No. 1078 or 1080 steel). Depending on cost considerations, other steels, such as alloy steels, might be employed.

Wear-resistant chipping end surfaces are provided on the hammer head 14 in accordance with the invention by layers of tungsten carbide electrodeposited on the chipping end 44. Referring to FIGS. 2-6, a layer 54 of tungsten carbide is deposited at the top bevel face 48 adjacent the cutting edge 52 therealong, from one lateral blade edge 42 to the opposite edge 42. Similarly, a layer 56 of tungsten carbide is deposited at the bottom bevel face 50 adjacent the cutting edge 52 therealong. Layers 58 of tungsten carbide are deposited at the respective lateral blade edges 42 adjacent the cutting edge 52, such layers preferably extending across the edges and extending longitudinally from the cutting edge 52 for a distance along the lateral edges 42 beyond their intersections with the bottom bevel face 50, in the direction of the medial body portion 16. Thus, the lateral edge layers 58 may extend inwardly from the cutting edge 52 for a distance of about one and one-half to two times the inward extent of the inner margin 60 of the bottom bevel face 50.

The tungsten carbide layers 54, 56 and 58 form outer surfaces on the respective bevel face 48, bevel face 50, and lateral blade edges 42 at the chipping end 44, and the layers also penetrate the blade portion 20, as illustrated in FIG. 6. Electrodeposition causes molecular tungsten carbide to penetrate the bevel faces and lateral blade edges, forming deposits within the blade portion 20. Also, carbide deposits build up on the surfaces of the bevel faces and lateral blade edges, thereby forming outer surfaces thereon. In the preferred practice of the invention, the layers 54, 56 and 58 formed by such carbide deposits penetrate the blade portion 20 for about one-half of the layer depth. It is also preferred that the depth or thickness of each layer 54, 56 and 58 be on the order of 0.004 inch, with the layer extending into the blade portion 20 for about 0.002 inch.

The hammer is used for breaking bricks in the same manner as a conventional bricklayers hammer.

Thus, the brick mason grips the hammer by the grip section 24 and chips a line or groove across one side of the brick with the chipping end 44, ordinarily while holding the brick in one hand. The line or groove should be straight and of substantially constant depth, and to insure this result, the cutting edge 52 should be sharp and straight. A dull edge does not produce a clean cut, and a rounded edge makes it difficult to draw a straight line. The mason next turns the brick over in his hand, and strikes the brick with the impact head proper 18. The brick most desirably is struck with one of the square edges 40 at the striking face 32, with the edge in a perpendicular plane through the brick with the line or groove chipped on the opposite side of the brick, to produce a clean break.

The tungsten carbide layers 54, 56 and 58 are applied in a very simple, convenient and rapid manner employing conventional equipment for electrodeposition of the carbide, which is commercially available. The layers are applied by means of a spark discharge from a tungsten carbide electrode subjected to an electrical potential, in a hand-held electromagnetic vibratory electrical tool, which interrupts the current at a regular frequency, e.g., 120 pulses per minute. The

electrode is placed against or closely adjacent to a I bevel face 48 or 50, or a lateral blade edge 42, and tungsten carbide is discharged from the electrode and deposited beneath and on the adjacent surface, in a depth or thickness depending upon the spark gap and the potential. The electrode is moved over the surface of the bevel face 48, bevel face 50, or a lateral blade edge 42, to form the corresponding layer 54, 56 or 58 thereover. The tungsten carbide is fused into the blade portion 20 and deposited thereon without overheating the surfaces thereof and affecting their properties.

Available equipment included Model 312 Rocklinizer (Rocklin Manufacturing Co.), which is employed at its maximum dial setting to provide a tungsten carbide layer of about 0.004 inch depth, in each case. It is preferred to provide such layer depth corresponding to the capacity of the particular equipment, although lesser depths may be provided while yet achieving improved results in accordance with the invention. Greater layer depths may be provided, but do not appear to be needed. Another brand of available equipment is identified as Carbumatic (Mercuria Company, Inc.). The commercial equipment was previously employed for coating machine tools and dies.

The surfaces formed by the tungsten carbide layers 54, 56 and 58 are extremely wear-resistant. The layers 54 and 56 on bevel faces 48 and 50 preserve the cutting edge 52 from wear, keeping the cutting edge sharp and straight. The layers 58 on the lateral bladeedges 42 preserve the lateral edges from wear and consequent rounding of the corners of the chipping end 44, thus also serving to keep the cutting edge 52 sharp and straight.

The hammer 10 gave remarkable service when field tested under the severe conditions peculiar. to brick masonry. When the hammer was used for breaking paving bricks, which are extremely hard and abrasive, it was found that the original cutting edge 52 was maintained over a period of time which would have consumed four or five of the conventional hammers, having no tungsten carbide layers. in addition, each of the conventional hammers would have required a number of blade sharpenings before being replaced, whereas the hammer of the invention required no sharpening.

The invention thus provides a markedly superior bricklayers hammer having a blade portion which performs like a new tool throughout a long service life, without dulling or rounding; The brick mason is able to chip a uniform straight line across a brick repeatedly,

with no loss of precision and with no need for sharpening the blade portion, producing clean breaks and thereby high quality work with minimal waste.

While a preferred embodiment of the inventionhas been described and illustrated, it will be apparent to those skilled in the art that various changes and modifications may be made within the spirit and scope of the invention. It is intended that such changes and modifications be included within the scope of the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a forged steel bricklayers hammer head including a medial body portion, an impact head proper integral with said body portion and projecting outwardly from one end thereof, and a blade portion integral with of said lateral edges adjacent said cutting edge, said layers being deposited by a spark discharge from a tungsten carbide electrode to preserve the blade portion properties, said layers forming outer surfaces on said bevel faces and said lateral edges and penetrating said blade portion for about one-half of the layer depth, thereby providing wear-resistant surfaces on said chipping end. 

